The present invention relates to rotary Wankel type engines, and more particularly to such an engine which provides improved operation in the form of reduced oil and gas leakage, improved lubrication, improved crankshaft bearing support and improved fuel charging.
Exemplary rotary type engines are shown in U.S. Pat. Nos. 3,996,898; 3,694,113; 3,228,183; and 3,259,115, and in German (Democratic Republic) patent document no. 26759.
Rotary Wankel type engine systems known in the art suffer from various drawbacks which have prevented such systems from achieving maximum engine performance and reliability. Such problems include high leakage of the rotor apex and side seals, causing overheating and lubrication contamination, and crankshaft bending for lack of a sufficient center main bearing support, causing side housing gouging and limiting maximum engine RPM under high compression firing loads.
The German patent document no. 26759 (Straube) illustrates a sealing arrangement apparently used in a rotary engine. This arrangement does not appear to provide an effective end seal in contact with the side seals. It also appears that the side seals restrict movement of the apex seals; the side seals will tend to jamb against the apex seals from the effects of rotation of the rotor.
U.S. Pat. No. 3,228,183 discloses a rotary internal combustion engine which is apparently a two stage diesel type engine. While the reference discloses two spark plugs, fuel is not injected laterally between the sparkplugs for stratified area charge. Moreover, the spark plugs are not equally spaced from the injectors, and therefore the system does not provide maximum stratification.
U.S. Pat. Nos. 3,259,115 and 3,694,113 describe rotary engine designs which employ a crankshaft supported by split journal type bearing assemblies. A disadvantage of such bearing assemblies is that they fail to provide adequate lubrication flow to the crankshaft and engine components, due to the relatively tight tolerance fit of the bearing journals around the crankshaft.
U.S. Pat. No. 3,996,898 describes an apex seal arrangement for a rotary engine. The dual apex seals do not seal at the side walls laterally. Separate corner seal elements are employed.
It would therefore represent an advance in the art to provide an improved rotary Wankel type engine system with improved apex and side sealing, and with improved center support bearing means for proper support of the crankshaft during high RPM loading.